Analysis of fouling and flux behaviour in crossflow microfiltration of non-alcoholic beer by ceramic membrane

In: 7th International Conference on Membrane Science and Technology – MST2009, 12-15 May 2009, Kuala Lumpur, Malaysia.The clarification of rough non alcoholic beer (RNAB) constitutes a scientific and technical challenges for brewing industry as an alternative to conventional dead-end filtration with filter-aid (Kieselguhr). RNAB clarification has been investigated in a pilot plant including a tubular ceramic membrane with a nominal pore diameter of 0.45μm. The actual mean pore diameter of the membrane has been determined to be 2.4μm and the mean particles diameter in RNAB was 115μm. The concentration of suspended particles in the RNAB (in kg/m3) has been found to have a proportional relation with its turbidity (in NTU) with the factor of 4.45×10-4(kgm-3NTU-1). During cross-flow filtration, flux declined drastically with time due to the fouling. According to the characterizing curve of log(d2t/dV2) versus log(dt/dV), the mechanism of fouling has been determined to be pore blocking initially (standard blocking law) and cake formation mechanism successively (cake filtration law). Analysis of the first 15min of operation with pore blocking model and the remaining flux data after 20min of operation with cake filtration models represent a good agreement with correlation coefficient of more than 92%. A generalized equation has been derived for predicting the flux data and its application for other set of data was acceptable with less than 15% error. This evidenceconfirms that microfiltration of rough non-alcoholic beer is controlled by formation of gel and cake layer on the surface of the membrane and hydrodynamic techniquesmay play a significant role in the flux enhancement and improving the performance of operation